Optical networks transmit data over optical fiber. In an optical network, multiplexing protocols such as Synchronous optical networking (SONET) and Synchronous Digital Hierarchy (SDH) may be used to transfer multiple digital bit streams over the same optical fiber. Lasers or light-emitting diodes (LEDs) may used to generate the optical carriers.
Bit streams traversing an optical network may pass through transponder switches. Such a switch may, for example, connect to multiple different fiber ports. Bit streams may be received at the switch, converted to an electrical signal, switched to the appropriate output port based on the electrical signal, converted back to an optical signal, and output as an optical signal on the determined output port.
The switching of an optical signal between ports in the transponder switch may involve the conversion of a serial bit stream into parallel chunks of data that are written to a memory. The data for the bit stream may subsequently be read out of the memory on a path corresponding to the determined output port and converted back to a serial stream. As the bandwidth of the transponder switch increases, the design and layout complexity of the switching circuitry may increase.